Kakuro
Fill the white squares so every run adds up to its clue.
How to play Kakuro
Kakuro is a number crossword. Instead of words, you write digits, and instead of hints, you get sums. The grid has white squares to fill and dark clue squares. A clue square is cut by a line. The number in the top right is the clue for the white squares to its right. The number in the bottom left is the clue for the white squares below it.
Goal
Write a digit from 1 to 9 in every white square. An unbroken line of white squares is called a run. The digits in each run must add up to the clue for that run, and a digit may not repeat inside a run. Every puzzle here has exactly one answer.
Step by step
- Pick a white square with a tap or a click, or move with the arrow keys. Its two runs light up, and their clues glow. The line under the grid tells you each sum and length, such as "Across 17 in 2".
- Enter a digit with the pad or with the keys 1 to 9.
- Turn on Notes (or press N) to keep small pencil marks of the digits that could fit.
- Use Erase or Backspace to clear a square, and Undo to take back a step.
- A digit used twice in a run turns red. A full run with the wrong total turns its clue red. A correct run fades its clue.
Levels
Easy puzzles are small, with short runs. Medium puzzles are 8×8. Hard puzzles are 10×10 with long runs that need careful thinking. Easy and Medium can always be solved with logic alone.
End of the game
The puzzle is solved when every white square holds the right digit. The timer stops and shows your time. Your game is saved in this browser, so you can stop and come back later. If you like number puzzles, try Sudoku or Calcudoku.
Strategy tips
- Learn the fixed sums. Some totals can be made only one way. 3 in two squares is always 1+2, 4 is 1+3, 16 is 7+9 and 17 is 8+9. With three squares, 6 is 1+2+3 and 24 is 7+8+9.
- Cross two runs. Where a run that needs 1 and 3 crosses a run that cannot hold 3, the square must be 1.
- Think about the largest and smallest digit. In a run of two that adds to 15, each digit must be 6 or more, since 9 is the biggest digit.
- Use notes. Write the possible digits in a square and cross them off as you fill in the runs around it.
- Remember no repeats. 4 in two squares can never be 2+2. This rule removes many options.
Kakuro FAQ
What do the two numbers in a clue square mean?
The top right number is the sum for the run to the right. The bottom left number is the sum for the run going down.
Can a digit repeat in a run?
No. Each run uses different digits. The same digit may appear again in another run.
Do the puzzles have one solution?
Yes. Each puzzle is checked by a solver before you see it, so there is exactly one correct answer.
Is my game saved if I leave?
Yes. The grid, your notes and the time are kept in this browser until you finish or start a new game.
